Effect of pressure change on position of equilibrium

Pressure changes ONLY affect gaseous rxn.

Le Chatelier's Principle : If pressure of an equilirium mixture is increased, position of equilibrium will shift in such a way as to decrease the pressure and a new equilibrium will achieved.

Examples :

1.               2SO2 (g) + O2 (g) ---> 2SO3 (g)

                       3 moles                    2 moles

In forward rxn, 3 moles of gaseous reactants changes into 2 moles of gaseous products. Hence, there is a decrease in no. of moles of gases, this leads to decrease in pressure.

When the pressure of equilibrium mixture is increased, more SO2 react with O2 to form SO3. The position of equilibrium will shift to the right in order to reduce…